﻿<p>An <em>IfcSweptSurface</em> is a surface defined by sweeping a curve. The swept surface is defined by a open or closed curve, represented by a subtype if <em>IfcProfileDef</em>, that is provided as a two-dimensional curve on an implicit plane, and by the sweeping operation.</p>
<ul>
<li>The swept curve is defined by positioning the profile in the xy plane of the object coordinate system, </li>
<li>The sweeping operation is applied to the swept curve as defined within the subtypes of <em>IfcSweptSurface</em>;</li>
</ul>
<p> The optional <em>Positio</em>n coordinate system allows for re-positioning the resulting swept surface relative to the object coordinate system.</p>
<blockquote class="extDef">NOTE&nbsp; Definition according to ISO/CD 10303-42:1992<br>
A swept surface is one that is constructed by sweeping a curve along another curve.</blockquote>
<blockquote class="note">NOTE&nbsp; Entity adapted from <strong>swept_surface</strong> defined in ISO
10303-42.</blockquote>
<blockquote class="history">HISTORY&nbsp; New entity in IFC2x.</blockquote>
<blockquote class="change-ifc2x4">IFC4 CHANGE&nbsp; The attribute <em>Position</em> has been changed to OPTIONAL with upward compatibility for file-based exchange.</blockquote>